New Space moves fast. Confidence in your data must keep pace.

Commercial Earth Observation missions face increasing pressure to shorten development cycles while delivering reliable, high-quality data. Mission design, algorithm development and data quality assessment all benefit from understanding what a sensor is expected to observe, even before the satellite is launched.

At high spatial resolution, 3D effects become increasingly important. Vegetation, buildings, terrain, shadows and atmospheric scattering influence measured radiances, particularly under off-nadir viewing geometries. Rayference brings physically-based 3D radiative transfer modelling to New Space, helping companies optimise mission design, generate realistic synthetic EO datasets and assess the quality of their observations throughout the mission lifecycle.

From mission concept to trusted Earth Observation data

From realistic 3D Earth scenes to simulated satellite observations

Rayference combines two complementary open-source technologies to simulate the complete observation process, from the physical properties of the Earth and atmosphere to the measurements recorded by an optical sensor.

Eradiate – The physics behind the simulations. Eradiate is an advanced Monte Carlo 3D radiative transfer model developed by Rayference. It simulates the interaction of radiation with complex three-dimensional environments, including vegetation, buildings, terrain and the atmosphere. By explicitly accounting for multiple scattering, shadows and 3D radiative transfer effects, Eradiate provides the physical foundation for realistic Earth Observation simulations.

DTE-S2GOS – From Earth scenes to sensor observations. DTE-S2GOS, the Synthetic Scene Generator and Observation Simulator developed by Rayference for ESA’s Destination Earth initiative, builds on Eradiate to provide an integrated simulation workflow:

• 3D Scene Generation: Construct realistic Earth scenes from digital elevation models, land cover, vegetation, buildings and other geospatial datasets, including surface optical properties, surrounding buffer regions and atmospheric conditions.
• Radiative Transfer Simulation: Compute physically consistent radiance fields under prescribed illumination, atmospheric and viewing conditions using Eradiate.
• Observation Simulation: Generate synthetic ground-based, airborne and satellite observations, accounting for instrument characteristics such as spectral response, spatial resolution, point spread function and noise.

Both technologies are open source, enabling transparency, reproducibility and adaptation to specific mission requirements. DTE-S2GOS provides modular simulation workflows that can be deployed on cloud-based computing infrastructure. Together, they enable Rayference to deliver customised simulations, physically consistent reference datasets and scientific analyses tailored to your EO mission.

From open data to a 3D scene

From realistic simulations to mission-ready insights

Explore how physics-based 3D radiative transfer simulations support mission preparation, synthetic EO data generation and radiometric quality assessment.

Different sensors, seasons and resolutions

Digital twins of reference sites

We model instrumented calibration and validation sites in 3D, including the instruments themselves, so that ground measurements, reference-mission data and your own acquisitions can be compared within a single, consistent physical model.

At the Gobabeb site in the Namib Desert (HYPERNETS GHNA, RadCalNet GONA), we modelled the HYPERNETS mast and its Hypstar-XR radiometer in 3D and compared the simulated views with real photographs.

Because the instrument and its support are part of the scene, their effect on the measurement can be quantified: comparing simulations with and without the mast shows that, depending on the viewing geometry, the mast alone can change the observed reflectance by more than 1%. The same approach applies to any sensor and acquisition set-up, on the ground or in orbit. Read the full study on the DTE-S2GOS website.

Radiative transfer is what we do

• Developers of Eradiate, the open-source 3D radiative transfer model used in ESA and EUMETSAT calibration activities.
• Developing DTE-S2GOS, the synthetic scene generator and observation simulator for ESA's Destination Earth.
• Experience in vicarious calibration for EUMETSAT and ESA missions, with hyperspectral simulations within ~3% of observations outside absorption bands.
• Developers of CISAR, an optimal-estimation retrieval of surface reflectance and aerosol properties with pixel-level uncertainties.
• A small, agile team used to working with industry and agencies, with open-source tools that avoid vendor lock-in.